<?php

/**
 * @ingroup database
 * @{
 */

/**
 * @file
 * Query code for MySQL embedded database engine.
 */


class InsertQuery_mysql extends InsertQuery {

	public function execute() {
		if (!$this->preExecute()) {
			return NULL;
		}

		// If we're selecting from a SelectQuery, finish building the query and
		// pass it back, as any remaining options are irrelevant.
		if (empty($this->fromQuery)) {
			$max_placeholder = 0;
			$values = array();
			foreach ($this->insertValues as $insert_values) {
				foreach ($insert_values as $value) {
					$values[':db_insert_placeholder_' . $max_placeholder++] = $value;
				}
			}
		}
		else {
			$values = $this->fromQuery->getArguments();
		}

		$last_insert_id = $this->connection->query((string) $this, $values, $this->queryOptions);

		// Re-initialize the values array so that we can re-use this query.
		$this->insertValues = array();

		return $last_insert_id;
	}

	public function __toString() {
		// Create a sanitized comment string to prepend to the query.
		$comments = $this->connection->makeComment($this->comments);

		// Default fields are always placed first for consistency.
		$insert_fields = array_merge($this->defaultFields, $this->insertFields);

		// If we're selecting from a SelectQuery, finish building the query and
		// pass it back, as any remaining options are irrelevant.
		if (!empty($this->fromQuery)) {
			return $comments . 'INSERT INTO {' . $this->table . '} (' . implode(', ', $insert_fields) . ') ' . $this->fromQuery;
		}

		$query = $comments . 'INSERT INTO {' . $this->table . '} (' . implode(', ', $insert_fields) . ') VALUES ';

		$max_placeholder = 0;
		$values = array();
		if (count($this->insertValues)) {
			foreach ($this->insertValues as $insert_values) {
				$placeholders = array();

				// Default fields aren't really placeholders, but this is the most convenient
				// way to handle them.
				$placeholders = array_pad($placeholders, count($this->defaultFields), 'default');

				$new_placeholder = $max_placeholder + count($insert_values);
				for ($i = $max_placeholder; $i < $new_placeholder; ++$i) {
					$placeholders[] = ':db_insert_placeholder_' . $i;
				}
				$max_placeholder = $new_placeholder;
				$values[] = '(' . implode(', ', $placeholders) . ')';
			}
		}
		else {
			// If there are no values, then this is a default-only query. We still need to handle that.
			$placeholders = array_fill(0, count($this->defaultFields), 'default');
			$values[] = '(' . implode(', ', $placeholders) . ')';
		}

		$query .= implode(', ', $values);

		return $query;
	}
}

class TruncateQuery_mysql extends TruncateQuery {
	public function __toString() {
		// TRUNCATE is actually a DDL statement on MySQL, and DDL statements are
		// not transactional, and result in an implicit COMMIT. When we are in a
		// transaction, fallback to the slower, but transactional, DELETE.
		if ($this->connection->inTransaction()) {
			// Create a comment string to prepend to the query.
			$comments = $this->connection->makeComment($this->comments);
			return $comments . 'DELETE FROM {' . $this->connection->escapeTable($this->table) . '}';
		}
		else {
			return parent::__toString();
		}
	}
}

/**
 * @} End of "ingroup database".
 */
